Method and apparatus for improving connectivity between optical devices using software defined networking

ABSTRACT

Method and apparatus of a network configuration configured to permit a dense wavelength division multiplexing (“DWDM”) element to connect to a storage server, an Internet Protocol (“IP”) router, and DWDM network are disclosed. The configuration includes the DWDM network, storage area network (“SAN”) server, IP router, and optical transport network (“OTN”) switch. While the DWDM network transports information via optical fibers, the DWDM switch is coupled to the DWDM network for transporting optical signals. The SAN server is coupled to a port of the DWDM switch and is configured to store data at a remote location. The IP router which is coupled to the DWDM switch facilitates IP traffic between a user and the DWDM network. The OTN switch, coupled to the first DWDM switch, is capable of processing at least a portion of the optical signals.

PRIORITY

This patent application is a continuation of U.S. patent application ofU.S. patent application Ser. No. 14/640,797, filed on Mar. 6, 2015 inthe name of the same inventor and entitled “Methods and Apparatus forImproving Connectivity between Optical Devices using Software DefinedNetworking,” hereby incorporated into the present application byreference.

FIELD

The exemplary embodiment(s) of the present invention relates totelecommunications network. More specifically, the exemplaryembodiment(s) of the present invention relates to optical networking.

BACKGROUND

With increasing demand for more information to be supplied to homesand/or businesses, network providers are constantly adding, expanding,upgrading, and/or switching their networks to improve overall opticalcommunications network(s). Optical communications networks typicallyoffer high-speed voice, video, and data transmission between users, suchas providers, residential homes, businesses, government agents, and/ornetworks. Conventional optical networks include, but not limited to,fiber to the node/neighborhood (“FTTN”), fiber to the curb (“FTTC”),fiber to the building (“FTTB”), fiber to the home (“FTTH”), fiber to thepremises (“FTTP”), or other edge location to which a fiber networkextends. With increasing speed and capacity, optical networking becomesan integral part of digital communications network. To improveversatility of the optical network, various optical devices such aswave-division multiplexing (“WDM”) elements have been developed tomanipulate optical signals, such as routing, splitting, merging, and/ordropping optical signals.

To route optical signals between various optical nodes or devices, a WDMsystem, for example, may be employed to handle optical routing. The WDMsystem, for certain applications, is able to multiplex a number ofoptical signals with different wavelengths onto a single optical fiber.A wavelength may also be referred as a frequency or a color capable oftraveling across an optical fiber. Different wavelengths, for instance,can be generated by different lasers. With a WDM network environment, atypical fiber may be configured to carry multiple sets of networktraffic using different traffic wavelengths. For instance, a fiber canbe configured up to 88 channels wherein each channel can transmit aspecific type of wavelength containing optical information.

A conventional network includes multiple nodes. Each node is typicallycoupled with other nodes via one or more connections such as opticalfibers and/or electrical cables. Since each fiber or optical fiber cancarry multiple sets of frequencies or degrees of data traffic,inter-office fiber optic cabling at the node can be complicated. Forexample, a typical optical node can handle multiple degrees of datatraffic using multiple fibers or fiber jumpers to route and/or processoptical signals.

A problem associated with a typical optical network is that theconnections between ports for facilitating traffic flow is predominantlyprovisioned as the static or permanent connections or links betweennetwork elements. A drawback associated with the static connection isthat establishing a static link for handling short lived (hours,minutes, and/or seconds) connections, also known as “On Demand”services, is not the best approach to utilize the network resource.

SUMMARY

One embodiment of the present invention discloses a networkconfiguration configured to permit a dense wavelength divisionmultiplexing (“DWDM”) element or switch to connect to a storage serverand an Internet Protocol (“IP”) router are disclosed. The configuration,in one aspect, includes a DWDM network, a storage area network (“SAN”)server, an IP router, and an optical transport network (“OTN”) switch.While the DWDM network transmits information via optical fibers, theDWDM switch routes optical signals to their destinations via the DWDMnetwork. The SAN server is coupled to a port of the DWDM switch and isconfigured to backup data at a remote location. The IP router which iscoupled to the DWDM switch facilitates IP traffic between users via theDWDM network. The OTN switch, coupled to the first DWDM switch, iscapable of processing and/or grooming at least a portion of the opticalsignals.

Additional features and benefits of the exemplary embodiment(s) of thepresent invention will become apparent from the detailed description,figures and claims set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary embodiment(s) of the present invention will be understoodmore fully from the detailed description given below and from theaccompanying drawings of various embodiments of the invention, which,however, should not be taken to limit the invention to the specificembodiments, but are for explanation and understanding only.

FIG. 1 is a block diagram illustrating an optical network configurationor topology using a DWDM switch to transmit optical data in accordancewith one embodiment of the present invention;

FIG. 2 is a block diagram illustrating an optical network configurationor topology using a DWDM switch to receive optical data in accordancewith one embodiment of the present invention;

FIG. 3 is a block diagram illustrating a reconfigurable optical add-dropmultiplexer (“ROADM”) used in a DWDM switch in accordance with oneembodiment of the present invention;

FIGS. 4-5 are block diagrams illustrating exemplary alternativeconfigurations or topologies using DWDM switches in accordance with oneembodiment of the present invention;

FIGS. 6A-6B are flowcharts illustrating alternative configurations inaccordance with one embodiment of the present invention; and

FIG. 7 is a flowchart illustrating an exemplary process of DWDM switchcapable of communicating with SAN server and IP router in accordancewith one embodiment of the present invention.

DETAILED DESCRIPTION

Exemplary embodiment(s) of the present invention is described in contextof a method and/or apparatus for node connectivity and port assignmentsrelating to optical networking.

The purpose of the following detailed description is to provide anunderstanding of one or more embodiments of the present invention. Thoseof ordinary skills in the art will realize that the following detaileddescription is illustrative only and is not intended to be in any waylimiting. Other embodiments will readily suggest themselves to suchskilled persons having the benefit of this disclosure and/ordescription.

In the interest of clarity, not all of the routine features of theimplementations described herein are shown and described. It will, ofcourse, be understood that in the development of any such actualimplementation, numerous implementation-specific decisions may be madein order to achieve the developer's specific goals, such as compliancewith application- and business-related constraints, and that thesespecific goals will vary from one implementation to another and from onedeveloper to another. Moreover, it will be understood that such adevelopment effort might be complex and time-consuming, but wouldnevertheless be a routine undertaking of engineering for those ofordinary skills in the art having the benefit of embodiment(s) of thisdisclosure.

Various embodiments of the present invention illustrated in the drawingsmay not be drawn to scale. Rather, the dimensions of the variousfeatures may be expanded or reduced for clarity. In addition, some ofthe drawings may be simplified for clarity. Thus, the drawings may notdepict all of the components of a given apparatus (e.g., device) ormethod. The same reference indicators will be used throughout thedrawings and the following detailed description to refer to the same orlike parts.

The term “system” or “device” is used generically herein to describe anynumber of components, elements, sub-systems, devices, packet switchelements, packet switches, access switches, routers, networks, computerand/or communication devices or mechanisms, or combinations ofcomponents thereof. The term “computer” includes a processor, memory,and buses capable of executing instruction wherein the computer refersto one or a cluster of computers, personal computers, workstations,mainframes, or combinations of computers thereof.

Communication network means any type of network that is able to transmitdata in a form of packets, cells, or frames. A communication network maybe, for example, an IP communication network or an IP network carryingtraffic packed in cells such as ATM (Asynchronous Transfer Mode) type,on a transport medium, for example, the TCP/IP or UDP/IP type. ATM cellsare the result of decomposition (or segmentation) of packets of data, IPtype, and those packets (here IP packets) comprise an IP header, aheader specific to the transport medium (for example UDP or TCP) andpayload data. The IP network may include one or more of a satellitenetwork, a DVB-RCS (Digital Video Broadcasting-Return Channel System)network, an SDMB (Satellite Digital Multimedia Broadcast) network, aterrestrial network, a cable (xDSL) network or a mobile or cellularnetwork (GPRS/EDGE, or UMTS (where applicable of the MBMS (MultimediaBroadcast/Multicast Services) type, the evolution of the UMTS known asLTE (Long Term Evolution), or DVB-H (Digital VideoBroadcasting-Handhelds)), a hybrid (satellite and terrestrial) network,and/or an optical network.

An optical network uses light or photon energy to transmit informationbetween various nodes of a communications network. The nodes can beplaced within site(s), regional geographic locations, and/ormetropolitan areas. To properly handle the light transmission, variousoptical devices or optical network element (“NE”), such as opticalamplifiers, lasers, wave divisional multiplexing (“WDM”) are used totransmit data across fiber-optic cables.

One embodiment of the present invention discloses a networkconfiguration or topology configured to allow a DWDM NE or switch tocouple to a storage server and an IP router. A DWDM NE can also bereferred to as a DWDM switch, DWDM router, DWDM hub, DWDM machine, andthe like. The configuration, also known as network topology, can includea DWDM network, a storage area network (“SAN”) server, IP router, DWDMNE, and/or OTN switch.

A DWDM network links multiple geographically separated nodes togetherusing optical connections as well as one or more DWDM switches. Afunction of DWDM switch is to transmit optical signals to theirdestinations via the DWDM network. The SAN server, which contains DWDMcompliant transceiver(s), is connected to a port of the DWDM switch fordata backup at a remote location. The IP router, which is coupled to theDWDM switch, facilitates IP traffic between users, content providers,network providers, and/or enterprises. An OTN switch which is coupled tothe first DWDM switch is capable of processing and/or grooming at leasta portion of the optical signals before sending the signals. Forexample, the OTN switch is able to merge multiple small sections of datainto a larger entity of data that fills larger portion of a channelbefore transmitting the data.

FIG. 1 is a block diagram 100 illustrating an optical networkconfiguration or topology using a DWDM switch to transmit optical datain accordance with one embodiment of the present invention. Diagram 100includes a DWDM switch 106, DWDM network 102, OTN switch 108, SAN Server110, and IP router 112. In one aspect, IP router 112 is coupled toserver 114 and base station 116 wherein base station 116 provideswireless communication between end users such as mobile 118. It shouldbe noted that the underlying concept of the exemplary embodiment(s) ofthe present invention would not change if one or more components (orelements) were added to or removed from diagram 100.

DWDM network 102 is an optical communication network capable ofmultiplexing multiple optical carrier (“OC”) signals onto one fiber fortransporting information from one or more sources to one or moredestinations. To multiplex multiple OC signals, different wavelengths(i.e., colors) of DWDM compliant lasers may be employed. DWDM network102 also enables bidirectional communications over a single fiber usingdifferent wavelengths. In a WDM system, various types of multiplexersare used at the transmitter or near the transmitter for mergingdifferent wavelengths. Demultiplexer can also be used at the receivingend or near the receiver to separate wavelengths. DWDM network 102logically connects multiple nodes that are separated by geographicdistances (i.e., network nodes) for network communication.

DWDM switch 106, also known as DWDM element or DWDM NE (networkelement), is able to transmit and receive optical signals to and fromDWDM network 102. DWDM switch 106, in one aspect, includes a networkinterface 120, a device interface 122, an OTN bypass module 190, inputports 150-156, and output ports 130-136. Interfaces 120-122 and module190 can be hardware, software, and/or a combination of hardware andsoftware components. Network interface 120 is capable of facilitatingoptical communication between DWDM network and end user (“EU”) devicessuch as SAN server 110 or IP router 112. For example, network interface120 is able to receive the groomed data from OTN switch 108. Networkinterface 120 is also able to receive fully channeled traffic frombypass multiplexer 192 bypassing OTN switch 108.

Device interface 122 facilitates communication among/between variousdevices such as, for example, EU devices, OTN switch 108, and OTN bypassmodule 190. In one embodiment, device interface 122, OTN bypass module190, and network interface 120 are integrated into one component. Forinstance, DWDM switch 106 includes one or more reconfigurable opticaladd-drop multiplexers (“ROADMs”) to implement network interface 122,device interface 120, and/or OTN bypass module 190. The ROADM, in oneaspect, is able to route optical signals from SAN server 110 and/or IProuter 112 to OTN switch 108 or directly to DWDM network 102 dependingon the traffic. In addition, DWDM switch 106 also includes a networkprocessing module able to receive SAN traffic from a specific andpredefined SAN server 110, and subsequently forward the SAN traffic toOTN switch 108 for traffic grooming.

Input and output (“I/O”) ports 130-136 and 150-156 of DWDM switch 106,in one embodiment, are assigned to a set of specific devices. Forexample, I/O ports 130, 150 are used to communicate with DWDM network102, and I/O ports 132, 152 are assigned to communicate with OTN switch108. Also, while I/O ports 134, 154 are allocated to communicate with IProuter 112, I/O ports 136, 156 are dedicated to talk with SAN server110. In the forgoing description, I/O ports 136, 156 may also bereferred to as SAN I/O ports and I/O ports 134, 154 are referred to asIP I/O ports.

SAN server 110 includes storage 126 and I/O ports 140, 160 wherein theI/O ports 140, 160 are coupled to the SAN I/O ports of DWDM switch 106.SAN server 110 is dedicated to store or backup data at a remote locationusing SAN. SAN is generally not accessible through the local areanetwork (“LAN”) by other devices. EU 146, which can be a bank, iscoupled to SAN server 110 for storage backup during off-peak hours viaDWDM network 102. To communicate directly to DWDM switch 106, SAN server110, in one aspect, includes a DWDM transceiver which can be part of I/Oports 140 or 160 to facilitate communication between SAN server 110 andDWDM switch 106 using WDWM signals. For example, output port 140 of SANserver 110 is coupled to the SAN input port 156 of DWDM switch 106 via afiber 170 and is capable of sending a DWDM compliant optical signal fromoutput port 140 to SAN input port 156 for storing data at a remotelocation. It should be noted that a DWDM transceiver is a DWDM complianttransmitter and receiver capable of handling DWDM wavelengths. Forinstance, a DWDM transceiver includes at least one DWDM compliant lasercapable of generating and sending optical signals to a ROADM in the DWDMswitch 106.

OTN switch 108 includes one or more optical network elements (“ONEs”)124 and I/O ports 138, 158, wherein ONEs are connected to I/O ports 138,158 via optical connections such as connection 178 to providefunctionality of transporting, multiplexing, switching, managing, andmonitoring optical channels carrying data signals. For inter-domaininterfaces, OTN switch 108 is able to provide multiplexing functionsincluding re-time, re-amplify, and re-shape (“3R”). In one aspect, OTNswitch 108 includes a grooming module configured to provide trafficgrooming involving traffic flows from SAN server 110 and IP router 112.

IP router 112 includes DWDM I/O ports 142, 162 and IP ports wherein theIP ports are coupled to server 114 and base station 116. Server 114, inone example, can be a content provider. Base station 116 is logicallyconnected to multiple EUs via a wireless communication. IP router 112,in one embodiment, includes a DWDM compliant transceiver capable ofcommunicating directly with DWDM switch 106. For instance, DWDM outputport 142 is coupled to input IP port 154 via a fiber 171 for sending IPtraffic. DWDM input port 162 coupled to output IP port 134 is able toreceive optical data from output IP port 134 of DWDM switch 106.

The network configuration or topology illustrated in diagram 100 permitsEU devices such as SAN server 110 and IP router 112 to directly connectto DWDM switch 106 instead of coupling to OTN switch. A benefit of thenetwork topology is to save ports on the OTN switch(s) for certainnetwork services such as on-demand services. The on-demand services, forexample, are network services that switch periodically such as daily orweekly as opposed to long lived. The long lived switch or connectionmeans connections remaining for a long period of time such as months oryears depending on the applications. A bank, for example, backs up itsdata remotely during the nighttime which general requires a bandwidth oftransmission for a short period of time on a periodical (i.e., daily)basis.

To manage time based services or on-demand services with enterprisequality of service, Software Defined Networking (“SDN”) has beenemployed to achieve such time based traffic management. SDN, in oneexample, allows user or administrator to control the network servicesvia lower-level functionality. SDN facilitates communication between thecontrol plane and the data plane. To optically switch between NEs withina node or location, the DWDM system such as DWDM switch 106 may useroute and select switching within such switches.

During a daytime operation, IP router 112 sends DWDM compliant IPtraffic via output port 142 upon receipt of the IP traffic fromconnected EU devices, such as base station 112, server 114, or both.After arriving to IP input port 154 via fiber 171, the IP traffictravels to multiplexer or module 128 via connection 173. In oneembodiment, multiplexer 128 shuts off path 172 since SAN server 110should not send any traffic during the daytime. OTN bypass module 190subsequently determines whether the IP traffic needs OTN switch serviceor not. If, for example, the traffic grooming (i.e., multiplexing,amplifying, etc.) is needed for at least a portion of the IP traffic,OTN output port 132 forwards the portion of IP traffic to input port 158of OTN switch 108 via fiber 176. After traffic grooming, the processedIP traffic (or processed portion of the IP traffic) is forwarded fromoutput port 138 of OTN switch 108 to input port 152 of DWDM switch 106.Upon arriving, network interface 120 forwards the IP traffic which hasbeen groomed to DWDM network 102 via output port 130 and fiber 182. Ifthe traffic grooming is not necessary, OTN bypass module 190 activatesmultiplexer 192 allowing the IP traffic to bypasses OTN switch 108 anddirectly travel to network interface 120 via multiplexer 192. Forexample, if the IP traffic uses full channel capacity, grooming may notbe necessary and it can be sent directly to DWDM network 102.

During a nighttime operation, SAN server 110 instead of IP router 112sends DWDM compliant SAN traffic via output port 140 upon receipt of theSAN traffic from connected EU devices such as server 146. After arrivingto SAN input port 156 via fiber 170, the SAN traffic travels tomultiplexer 128 via connection 172. In one embodiment, multiplexer 128shuts off path 173 since it is the nighttime which is a designated timeperiod for SAN service. OTN bypass module 190 subsequently determineswhether the SAN traffic needs OTN service or not. If, for example,traffic grooming (i.e., multiplexing, amplifying, etc.) is needed, OTNoutput port 132 forwards the SAN traffic to input port 158 of OTN switch108 via fiber 176. After traffic grooming, the groomed SAN traffic isforwarded from output port 138 of OTN switch 108 to input port 152 ofDWDM switch 106. Upon arriving, network interface 120 forwards the SANtraffic which has been groomed to DWDM network 102 via output port 130and fiber 182. If the traffic grooming is not necessary, OTN bypassmodule 190 activates multiplexer 192 allowing the SAN traffic to bypassOTN switch 108 and directly travel to network interface 120 viamultiplexer 192.

An advantage of using the network topology illustrated in diagram 100 isthat it enhances nodal and/or device connectivity while maintainingsimilar OTN switch ports for network services.

FIG. 2 is a block diagram 200 illustrating an optical networkconfiguration using a DWDM switch to communicate with a DWDM network inaccordance with one embodiment of the present invention. Diagram 200 issimilar to diagram 100 illustrated in FIG. 1 except that diagram 200shows traffic received from DWDM network 102 by DWDM switch 106. Diagram200 includes DWDM switch 106, DWDM network 102, OTN switch 108, SANserver 110, and IP router 112. In one aspect, IP router 112 is coupledto server 114 and base station 116 wherein base station 116 provideswireless communication with end users such as mobile 118. It should benoted that the underlying concept of the exemplary embodiment(s) of thepresent invention would not change if one or more components (orelements) were added to or removed from diagram 200.

During an operation, an optical data flow is received at input port 150of DWDM switch 106 from DWDM network 102 via a connection or fiber 282.After reaching network interface 120, the data flow is forwarded to OTNswitch 108 if traffic processing such as demultiplexing of the data flowis needed. When the data flow arrives at input port 238 of OTN switch108 from output port 252 of DWDM switch, the data flow is processed byONE 224 of OTN switch 108. The processed data flow is subsequently sentfrom output port 258 of OTN switch 108 to input port 232 of DWDM switch106. The processed data flow is subsequently forwarded to IP output port134 if the destination of the data flow is IP router 112. Alternatively,if the destination of the data flow is SAN server 110, the processeddata flow is sent to SAN output port 136. If, however, the trafficprocessing is not necessary, OTN bypass module 290 is activated whichinstructs multiplexer 292 to allow the data flow to directly flow fromoutput 280 of network interface 120 to device interface 122.

An advantage of employing network configuration illustrated in diagram200 is to save ports on OTN switch (or equivalent) 108 for time basednetwork services such as On-Demand services. For example, the businessesthat back up their data remotely require bandwidth for a short periodtime. The backup process, in one aspect, can be done during the lateevening or night when IP services are at a low point. It should be notedthat DWDM optical transmission can also combine data flows withdifferent protocols.

The volume and speed requirements for IP traffic are generally greaterthan the requirements for SAN traffic. When the SAN traffic, forexample, grows past the full optical channel, a second channel isrequired and needs to be added. The second channel is an on-demandchannel with appropriate IP channel. To avoid increasing port numbers inthe OTN switch, network configuration or topology illustrated in diagram200 allows the channel(s) to be added to DWDM switch 106 instead of theOTN switch 108 whereby there is no need for full channel to route to theOTN switch 108 for grooming since it is routed by the DWDM switch 106.The connectivity is simplified and the number of ports on the OTN switch108 stays the same so that the overall device lifetime and efficiencyare enhanced.

An advantage of employing the network topology or configurationillustrated in diagram 200 is that the configuration is more adaptableto capacity expansion due to network demand. For example, the DWDMswitches can be provisioned to add additional ports for capacityexpansion.

FIG. 3 is a block diagram 300 illustrating a reconfigurable opticaladd-drop multiplexer (“ROADM”) used in DWDM switch 106 for opticalsignal routing or switching in accordance with one embodiment of thepresent invention. Diagram 300 includes OTN switch 108 and DWDM switch106 containing device interface 122. Device interface 122 furtherincludes a multi-degree ROADM that includes a line system 302,intra-nodal fiber connections 304, add-drop subsystems 306, and localtransponders 308. To simplify forgoing discussion, the DWDM network, IProuter(s), SAN server(s) are not included in diagram 300. It should benoted that the underlying concept of the exemplary embodiment(s) of thepresent invention would not change if one or more components (orelements) were added to or removed from diagram 300.

Line system 302, in one embodiment, includes one or more broadcast andselect wavelength divisional multiplexing (“B&S WDM”) line modules 312for routing or distributing optical signals. Optical signals includelight wavelengths, frequencies, light beams, photon energy, and/oroptical traffic. Each B&S WDM line module 312, also known as linemodule, includes a passive coupler or splitter 314, a wavelength selectswitch (“WSS”) 316, a line input amplifier (“IA”) 318, and a line outputamplifier (“OA”) 320. In one example, an amplifier such as an ErbiumDoped Fiber Amplifier (“EDFA”) is used for the line output amplifier 320and/or line input amplifier 318. Note that the line output amplifier 320is used to transmit an optical signal from line module 312. The lineinput is configured to allow an optical signal to enter line module 312.A function of passive coupler 314 is to receive multiplexed signal(s),wavelengths, or frequencies from IA 318 and subsequently forward thereceived signal(s) to various output ports 322. Select WSS 316 isconfigured to receive various signals or frequencies from input ports324 and subsequently forward a multiplexed optical signal to otheroptical modules via OA 320.

Intra-nodal fiber connections 304, in one aspect, include multipleoptical fibers and/or optical fiber jumpers used for coupling variousinput and output (“I/O”) ports between optical modules. In one example,intra-nodal fiber connections 304 include hundreds or thousands ofoptical fibers and/or jumpers for connecting and/or cabling I/O portslocated at the same or different optical modules. To simplify theconnections, a sorting device such as fiber shuffle may be used forfiber cabling and/or connecting.

Add-drop subsystem 306 illustrates multiple arrayed waveguides (“AWGs”)326 configured to provide fixed add and drop based optical routingfunction. It should be noted that optical routing function also ties tospecific degree and wavelength. For example, AWG 326 is able todistribute or route different optical signals with different wavelengthsupon receipt of an optical signal. The outputs from AWG 326 are fed toone or more transponders 330 based on a received optical signal such assignal 332. Note that signal 332 can be a multiplexed optical lightcontaining multiple sets of data. Alternatively, AWG 328 is also capableof receiving multiple different optical signals or frequencies whereinthe multiple signals are multiplexed into one multiplexed signal 336which is subsequently forwarded to one of input ports 324 of line module312 via intra-nodal fiber connections 304.

Local transponders 308 include multiple transponders 330 wherein eachtransponder 330 contains at least one pair of transmitter and receiver.In one aspect, transponder 330 is a wavelength-converting component thatis able to convert data signals between optical and electrical signals.In one example, transponders 330 are physically situated closer to theend users. Alternatively, transponders 330 are able to separatemulti-wavelength optical signal into individual data signals.

Diagram 300 illustrates a layout for a ROADM node which is used in aDWDM network environment. The DWDM network, for example, is able tohandle at least 10 gigabits optical data transmission on adispersion-managed fiber plant. Diagram 300 illustrates an N degreeROADM coupling to other ROADM modules in the network via fiber opticcables to N distant nodes, wherein N is an integer. Optical channels oninteroffice fibers may be dropped at local transponders 308 or expressedto some other degree, such as “pass through”, “transit”, switching of“express traffic”, or the like.

FIGS. 4-5 are block diagrams 400 and 500 illustrating exemplary networkconfigurations or topologies using DWDM switches as hubs in accordancewith one embodiment of the present invention. Diagrams 400 and 500include three (3) sites 402-408, DWDM network 102, and connections410-414 wherein connections 410-414 are used to facilitate communicationbetween sites 402-408. Sites 402-408 can also be considered as networknodes that are separated by geographic distances. Each site includes aDWDM NE, OTN NE, SAN server, and IP router wherein the DWDM NE orswitch, in one aspect, is used as hub for transmitting traffic flowsbetween the DWDM network and EU's devices, such as IP router, SANserver, and OTN NE, as illustrated in diagram 500.

Diagram 400 illustrates a first topology having site1 402, site2 406,and site3 408. Site1 402 includes a DWDM NE or switch 420, an OTN NE orswitch 422, a SAN server 424, and an IP router 426. Note that site1 402may include additional NEs, switches, hubs, servers, and the like, butthe additional device should not alter the underlying concept of thepresent embodiment. In one embodiment, SAN server 424 and IP router 426are coupled to OTN NE 420 via connections or fibers 428-429. OTN NE 422is able to access DWDM network 102 via the connections of DWDM NE 420.The term network element (“NE”) and switch can be used interchangeablyfor simplicity.

Diagram 500 illustrates a second network topology having site1 502,site2 506, and site3 508. The second network topology is similar to thefirst topology except that the second topology uses DWDM NE as a primaryNE for communicating between the DWDM network and EU devices such as SANservers and IP routers. In one aspect, the DWDM NE 420 is used as a hubof a node or site configured to provide or facilitate communicationbetween DWDM network 102 and SAN server 424, IP router 426, or OTNswitch 422. For example, site1 502 includes DWDM NE 420, OTN NE 422, SANserver 424, and IP router 426 wherein SAN server 424 and IP router 426are coupled or connected to DWDM NE 420 via connections or fiber528-529. OTN NE 422 is also coupled to DWDM NE 420 and able to processtraffic or a portion of the traffic if the traffic grooming isdesirable.

The first or second network topologies or configurations shown in FIGS.4 and 5 are capable of providing network services to one or more nodesor sites across one or more metropolitan areas with certain networkaccess patterns. For example, IP traffic between enterprise customersand/or users is high during the daytime or business hours, and is lowduring the evening hours. Residential access, however, ramps up duringthe evening hours. The residential usage generally drops off the daytime(business hours) or night hours. Since network usage for enterprise andresidential is generally minimal during the nighttime, it is usually agreat time for an enterprise such as a bank or financial institution tobackup its data to a remote location using SAN services.

The following examples show the different connectivity with differentport count or usage between the first network topology and secondnetwork topology. In the examples, four (4) gigabits per second (“Gb/s”)bandwidth is used as an exemplary capacity by SAN service during thenighttime network usage, and seven (7) Gb/s bandwidth of IP services isused as an exemplary capacity by IP service during the daytime and/orthe evening time. The SAN services are routed though the access networkto server such as SAN server 424. The IP traffic is general high duringthe daytime or even time while the SAN traffic is high during thenighttime. To simplify the examples, the SAN traffic is routed from Site1 to Site 2 and the IP traffic is routed from Site 1 to Site 3. In oneexemplary scenario, the network capacity grows four (4) Gb/s bandwidthin the SAN service and sever (7) Gb/S bandwidth in IP services everyyear or a period of time from the present time.

The first network topology as illustrated in diagram 400 illustrates anode network architecture capable of backing up data via SAN servers anddelivering IP services via IP routers. SAN traffic generated by SANserver 424 and/or IP traffic generated by IP router 426, for example,can be wrapped up or combined using the OTN protocol. It should be notedthat the traffic flows initiated by SAN or IP services do notnecessarily occupy the full bandwidth of the optical channel. To enhanceefficiency of optical network, traffic grooming which includes combiningtraffic flows can be desirable. In addition, multiple output ports maybe needed for the OTN switch because the destination of traffic flowsmay be different. The following example illustrates multiple stepsperformed by the first network topology illustrating connectivity andport counts over a period of time.

Step 1, (starting point) nighttime SAN traffic is routed from the SANserver to the OTN switch including four (4) Gb/s of traffic in a ten(10) Gb/s optical link. This requires a ten (10) Gb/s port on the IProuter connected to a ten (10) Gb/s port on the OTN switch. Another ten(10) Gb/s port as an output port of the OTN switch is needed to connectto the DWDM network onto Site 2. All of these optical links areapproximately 40% filled.

The IP traffic flows, during the daytime and/or evening, are routed fromthe IP routers to the OTN switches consisting of seven (7) Gb/s oftraffic in a ten (10) Gb/s rate optical link. A ten (10) Gb/s port onthe IP router is required to connect to a ten (10) Gb/s port on the OTNswitch. The same ten (10) Gb/s port used for the IP traffic output ofthe OTN switch can also be used to connect to the DWDM network onto site3. During the daytime or evening time, the OTN NEs switch off the SANtraffic and allow the IP traffic to reach its destination. During thenighttime, the OTN switches off the IP traffic and allows the traffic toreach site 3. Most of the optical links are likely 70% filled. Toaccomplish described operation, a number of ports (i.e., 10 Gb/s port)in the DWDM equipment including, but not limited to, OTN switches, SANservers, IP routers, and/or DWDM switches, needs to be identified andallocated. For example, the ten (10) Gb/s port count for the firstnetwork topology is five (5) since SAN server requires one (1) port, IProuter requires one (1) port, and OTN switch requires three (3) ports.

Step 2, (growth phase) traffic capacity and requirements grow or expandovertime. For example, to fulfill an expansion of requirement, new four(4) Gb/s traffic with a total of eight (8) Gb/s traffic is needed forSAN service. Since the eight (8) Gb/s is within the capacity of opticallink of ten (10) Gb/s, no additional port for connecting SAN server toOTN switch is required. The IP traffic requirements, however, double to14 Gb/s from seven (7) Gb/s routing from IP routers to OTN switches.Transmitting 14 Gb/s IP traffic may require two ten (10) Gb/s portswhereby an additional ten (10) Gb/s port is needed. The SAN traffic,however, can still fit in the ten (10) Gb/s port to the DWDM network butthe IP traffic will not fit. An additional ten (10) Gb/s port isrequired by the OTN switch for directing traffic to the DWDM NE. A ten(10) Gb/s connection from the SAN server to the OTN switch is needed,and two ten (10) Gb/s connections from the IP router to the OTN switchare required. Two ten (10) Gb/s connections from the OTN switch to theDWDM network are dedicated for communication. To accomplish thedescribed operation, a number of ports (i.e., 10 Gb/s port) in the DWDMequipment including, but not limited to, OTN switches, SAN servers, IProuters, and/or DWDM switches, needs to be identified and allocated. Forexample, the ten (10) Gb/s port count of the second network topology iseight (8) since SAN Server requires one (1) port, IP router requires two(2) ports, and OTN switch requires five (5) ports.

Step 3, (more growth) traffic capacity or requirements grow overtime.For example, additional four (4) Gb/s traffic with a total of 12 Gb/sfor SAN traffic is required for the SAN service. This requires oneadditional link from the SAN server to OTN switch since the additionaltraffic is beyond the capacity of a single ten (10) Gb/s link. The IPtraffic capacity or requirements increase to 21 Gb/s from 14 Gb/s. Thisrequires an additional ten (10) Gb/s ports from the IP router to OTNswitch for a total of three ten (10) Gb/s ports. The SAN traffic can fitin the ten (10) Gb/s port to the DWDM network but the IP traffic willnot fit. An additional ten (10) Gb/s port is required on the OTN switch.Two ten (10) Gb/s connections from the SAN server to the OTN switch areused and three ten (10) Gb/s connections from the IP router to the OTNswitch are used. Three ten (10) Gb/s connections from the OTN switch tothe DWDM network are required. To accomplish the described operation, anumber of ports (i.e., 10 Gb/s port) in the DWDM equipment including,but not limited to, OTN switches, SAN servers, IP routers, and/or DWDMswitches, needs to be identified and allocated. For example, the ten(10) Gb/s port count of the first network topology is thirteen (13)since SAN Server requires two (2) ports, IP router requires three (3)ports, and OTN switch requires eight (8) ports.

Step N, (more growth) traffic requirement continues to grow overtime.For example, SAN traffic grows four (4) Gb/s every year or everypredefined period of time while IP traffic increases seven (7) Gb/s forthe same period of time. The mathematical expression is N×4 Gb/s for SANtraffic and N×7 Gb/s IP traffic, wherein N is an integer. A total ofN_(SAN) 10 Gb/s ports from the SAN server to OTN switch and N_(IP) Gb/sports from the IP router to OTN switch are required. The mathematicalformula is, N_(SAN)=roundup (N×4/10) and N_(IP)=roundup (N×7/10) whereroundup means to roundup to the next highest integer. Note thatN_(SAN)<N_(IP) so there are N_(IP) 10 Gb/s links from the OTN switch tothe DWDM network.

Referring back to FIG. 4, diagram 400 illustrates one embodiment of thefirst network topology wherein the ten (10) Gb/s port count for thefirst network topology can be identified or calculated by the followingformula: 10 Gb/s port count equals to SAN Server N_(SAN)+IP routerN_(IP)+OTN switch N_(SAN)+N_(IP)+max(N_(SAN),N_(IP)), where N is aninteger.

The second network topology illustrated in FIG. 5 includes SAN servers,IP routers, OTN switches, and DWDM NEs wherein each DWDM NE isconfigured to couple to at least one SAN server, IP router, and OTNswitch. The DWDM NEs are also configured to communicate with other DWDMNEs situated in different sites or locations via the DWDM network suchas DWDM network 102. When channel capacity of an optical link is greaterthan the traffic flow, the traffic flow, in one example, is forwardedfrom the DWDM element to the OTN switch for traffic grooming. Forinstance, multiple small traffic flows could be merged or multiplexedonto a single optical link or channel. After traffic grooming, theprocessed traffic (or groomed traffic) is forwarded back to the DWDMelement for transmission. The following example illustrates multiplesteps performed by the second network topology providing connectivityand port count over a period of time.

Step 1: (starting point) Nighttime SAN traffic is routed from the SANserver consisting of four (4) Gb/s of traffic in a ten (10) Gb/s opticallink from the SAN server to the DWDM NE. When grooming is desirable, thetraffic is forwarded to the OTN switch from the DWDM NE. After OTNprocessing (or grooming) the processed traffic is sent back to the DWDMNE from the OTN switch. The traffic is subsequently routed to the DWDMnetwork.

The laser on the SAN server, in one embodiment, is a DWDM compliantdevice. In one aspect, the DWDM compliant device means a signal issufficiently narrow and the signals are generated within a predefinedrange of wavelengths whereby the signals can pass through the DWDMequipment. In one example, the DWDM equipment such as DWDM NE includes aspecial card to accommodate switching within a single node. The specialcard, for instance, may include ROADM component which is able to beplugged in the DWDM NE for node switching. A ten (10) Gb/s port of OTNswitch, for example, outputting traffic to DWDM network 102 through DWDMNE may contain data capacity less than 100% link capacity. For theinstant example, the link capacity is approximately 40% filled.

During the daytime and/or evening time, IP traffic is routed from the IProuter (i.e., IP router 426) to the OTN switch (i.e., OTN NE 422)consisting of seven (7) Gb/s of traffic in a ten (10) Gb/s rate opticallink via the DWDM NE, and then the processed traffic is sent from OTNswitch back to the DWDM NE. The traffic is outputted to the DWDM network(i.e., DWDM network 102) via the DWDM NE. The laser(s) used in the IProuter like the ones in the SAN server(s) are DWDM compliant lightemitting devices (“LEDs”).

A DWDM compliant device, in one example, generates a signal within anarrow range of predefined wavelength that allows the signal to passthrough the DWDM equipment. To handle DWDM signals, the DWDM NE requiresa special card or component such as ROADM component to handle the signalswitching within a node. The ten (10) Gb/s output port used for the IPtraffic of the OTN switch is used to connect to an input port of theDWDM NE whereby allowing the DWDM NE to forward the IP traffic to itsdestination via the DWDM network. To accomplish the described operation,the number of ports (i.e., 10 Gb/s port) in the DWDM equipment can beidentified and allocated. For example, the ten (10) Gb/s port count forthe second network topology is four (4) since SAN Server requires one(1) port, IP router requires one (1) port, and OTN switch requires two(2) ports.

Step 2: (growth phase) the traffic capacity and/or requirements grow orexpand overtime (or in a future time). For example, to fulfill anexpansion requirement, four (4) additional Gb/s traffic with a total ofeight (8) Gb/s traffic is required for the SAN traffic. Since the eight(8) Gb/s capacity is within the link capacity of ten (10) Gb/s, noadditional port for connecting SAN server to OTN switch is required. TheIP traffic requirements, however, double to 14 Gb/s from seven (7) Gb/srouting from the IP router to the OTN switch through the DWDM NE.Transmitting 14 Gb/s IP traffic requires two ten (10) Gb/s ports wherebyan additional ten (10) Gb/s port for the IP router may be needed.

Note that a portion of IP traffic four (4) Gb is routed from the IProuter to the OTN switch to groom the four (4) Gb/s traffic into a ten(10) Gb/s rate optical link. The groomed IP traffic is subsequentlyforwarded to the DWDM NE before it is being shipped to the DWDM network.Since the IP traffic destination is Site 3, a full ten (10) Gb/s link isused to route from the IP router through the DWDM NE to Site 3 via theDWDM network. To accomplish the described exemplary operation, thesecond network topology requires a number of ports (i.e., 10 Gb/s port)in the DWDM equipment. For example, the ten (10) Gb/s port count for thesecond network topology is five (5) since SAN Server requires one (1)port, IP router requires two (2) ports, and OTN switch requires two (2)ports.

Step 3: (future growth) traffic capacity and/or requirement continues togrow overtime. For example, an additional four (4) Gb/s for a total of12 Gb/s are required for the SAN traffic. During the nighttime, SANtraffic is routed from the SAN server to the OTN switch consisting of 2Gb/s of traffic in a ten (10) Gb/s optical link to the OTN switch fortraffic processing or grooming. After processing or grooming, thetraffic is forwarded back to the DWDM NE and the traffic is subsequentlyforwarded to its destination via the DWDM network. Since all traffic isdestined to Site 2, one full ten (10) Gb/s routing from the SAN serverthrough the DWDM NE, and subsequently forwarded it to Site 2 via theDWDM network.

The IP traffic capacity and requirements, in one aspect, grow to 21 Gbfrom previously 14 Gb routed from the IP router through the DWDM NE tothe OTN switch. 21 Gb/s IP traffic requires three (3) ten (10) Gb/sports to transmit. A new ten (10) Gb/s port in addition to the existingtwo ten (10) Gb/s ports of the IP router is needed. The IP traffic isrouted to Site 3 via the DWDM network and the DWDM NE. In one example,IP traffic is routed from IP router 426 to OTN switch 422 for groomingone (1) Gb/s of traffic in a ten (10) Gb/s rate optical link via DWDM NE420. After processing, the IP traffic which is just a portion of theentire IP traffic is routed from OTN switch 422 to DWDM network 102 viaDWDM NE 420. To accomplish the described exemplary operation, the secondnetwork topology requires a number of ports (i.e., 10 Gb/s port) in theDWDM equipment. For example, the ten (10) Gb/s port count of the secondnetwork topology is seven (7) since SAN Server requires two (2) ports,IP router requires three (3) ports, and OTN switch requires two (2)ports.

Step N: (future growth) traffic requirement continues to grow overtime,where N is an integer. For example, N×4 Gb/s of SAN traffic is requiredfor the nighttime data backup at a remote destination such as Site 2 forafter a period of time. To identify port requirement, the number of ten(10) Gb/s ports (N) required for SAN (N_(SAN)) can be calculated byrounddown (N×4/10) equals, where rounddown means to round down to thenext lowest integer. There are (N×4−N_(SAN)*10) Gb/s of SAN trafficrouted from the SAN server to the OTN switch in a ten (10) Gb/s opticallink from the SAN server to the DWDM NE. The SAN traffic is then sentback to the DWDM NE before being transmitted to the DWDM network. N×7Gb/s of IP traffic is required at night destined for Site 3. For IPtraffic, there are rounddown (N×7/10)=N_(IP) 10 Gb/s ports to the DWDMNE out to site 3. There are (N×4−N_(IP)*10) Gb/s of SAN traffic routedfrom the IP router to the OTN switch in a ten (10) Gb/s optical link.

Referring back to FIG. 5, diagram 500 illustrates one embodiment of thesecond network topology wherein the ten (10) Gb/s port count can beidentified or calculated by the following mathematic formula: ten (10)Gb/s port count equals SAN server N_(SAN), IP router N_(IP), and OTNswitch 2, where N is an integer.

FIGS. 6A-6B are flowcharts 600-601 illustrating two network topologiesor configurations in accordance with one embodiment of the presentinvention. Flowchart 600 illustrates a process of a first networktopology illustrated in FIG. 4. At block 602, the process adds trafficfor a type of service such as SAN service or IP service. The process, inone embodiment, determines at block 604 whether the traffic capacityexceeds the link capacity. If it does, the process proceeds to block608. At block 608, a new channel to OTN switch is provisioned orobtained. After provisioning, the traffic is routed to DWDM NE whichsubsequently sends the traffic to the end office via the DWDM network.If, at block 604, the traffic capacity does not exceed the linkcapacity, the process proceeds to block 606 where the additional trafficis added to the existing connection to the OTN switch. After addingtraffic to the existing link channel, the process sends the traffic withthe added traffic to the end office via DWDM NE.

Flowchart 601 illustrates a process of the second network topologyillustrated in FIG. 5. At block 622, the process adds traffic to a typeof service such as SAN service or IP service. The process, in oneembodiment, determines at block 624 whether the added traffic exceedsthe link capacity. If it does, the process proceeds to block 628. Atblock 628, while the full channeled traffic are sent to the end officevia DWDM NE, the remaining traffic is forwarded to the OTN switch fortraffic grooming. If, at block 624, the added traffic does not exceedthe link capacity, the process proceeds to block 626 where theadditional traffic is added to the existing connection to the OTNswitch. After grooming and/or processing by the OTN switch, the trafficwith the added traffic is sent to the end office via DWDM NE.

The second network topology uses SDN to save certain number of ports onthe OTN switch so that the second network topology is more adaptable tothe future network growth. The use of optical switching managed throughSDN provides an automated way of evolving to more efficient opticalnetwork. There are variations of this algorithm based on networktopology, actual traffic growth or other factors. One variation is thecommon use of the port on the OTN switch or WDWM NE. The traffic fromthe SAN server and the IP router can be running at different time andthere can use the common ports on the OTN switch. The SAN protocols areusually different from the IP protocols. However, the IP protocols usedfor web-surfing and/or file transfer are the same protocols whereby theycould share the common port(s). Also, the video services (dominate inevening traffic) may also be similar to IP protocol(s) and can use thesame common ports.

Another variation is different bit rates or speeds of traffic flows.Depending on the applications, a SAN server may use 8 Gb/s, 40 Gb/s, 100Gb/s, or the like based on the configuration of the network. It shouldbe noted that the transmissions in the DWDM system are bit-rateindependent if the traffic passes through the DWDM element.

Another variation is the type of equipment. Note that the SAN server andthe IP router can be connected to multiplexing cards in the DWDM NE. Thesecond network topology uses one multiplexing card for SAN traffic, onemultiplexing card for IP traffic, and allows full channels passingdirectly through the DWDM element from DWDM compliant optics on each ofthe servers.

Table 1 (see below) illustrates a summary showing OTN ports used orsaved in connection to first network topology (“FNT”) shown in FIG. 4and second network topology (“SNT”) shown in FIG. 5. Table 1 uses four(4) Gb/s of SAN traffic and seven (7) Gb/s of IP traffic. Table 1 showsOTN port requirement in view of number of destinations and number ofsteps.

TABLE 1 OTN ports 1 destination 2 destinations 3 destinations Step FNTSNT FNT SNT FNT SNT 1 3 3 6 4 8 5 2 5 3 7 4 9 5 3 8 3 11 4 11 5 4 8 3 114 11 5 5 10 3 12 4 15 5 6 13 3 18 4 17 5 7 13 3 18 4 17 5 8 16 3 20 4 225 9 18 3 23 4 26 5 10 18 3 23 4 26 5

The exemplary embodiment of the present invention includes variousprocessing steps, which will be described below. The steps of theexemplary embodiment of the present invention may be embodied in machineor computer executable instructions. The instructions can be used tocause a general purpose or special purpose system, which is programmedwith the instructions, to perform the steps of an exemplary embodimentof the present invention. While embodiments of the present inventionwill be described with reference to the DWDM network, the method andapparatus described herein is equally applicable to other networkinfrastructures or other data communications environments.

FIG. 7 is a flowchart 700 illustrating an exemplary process of DWDMswitch capable of communicating with SAN server and IP router inaccordance with one embodiment of the present invention. At block 702, aprocess capable of transmitting optical data via DWDM network is able toreceive a storage backup transmission from a first SAN server via afirst DWDM optical signal. In one example, optical data generated inaccordance with DWDM standard is received at a first SAN input port ofthe DWDM switch.

At block 704, a first IP traffic from a first IP router via a secondDWDM optical signal generator is received. In one aspect, the process iscapable of receiving an optical data flow generated in accordance withthe DWDM standard at a first IP input port of the DWDM switch.

At block 706, the IP traffic is redirected to a first OTN switch from anOTN output port of the DWDM switch for processing at least a portion ofthe first IP traffic such as traffic grooming. After processing, theprocessed or groomed first IP traffic from the OTN switch is received atan input port to the DWDM switch. For example, various small IP trafficor data flows may be grouped or regrouped into larger entities beforetransmission.

At block 708, the processed first IP traffic is transmitted via theoutput port of the DWDM switch to its destination via the DWDM network.In one aspect, the storage backup transmission can also be redirected orforwarded to the first OTN switch from the OTN output port of the DWDMswitch for processing or grooming if the SAN traffic or at least aportion of the SAN traffic needs to be processed before transmission.After processing, the groomed (or processed) SAN traffic (or storagebackup transmission) is forwarded to the input port to the DWDM switchfrom the OTN switch. Alternatively, the process is also capable ofreceiving second SAN traffic from a second SAN server. The second SANtraffic is represented by a set of second SAN DWDM optical signalsgenerated by a DWDM compliant laser or generator. Upon redirecting theSAN traffic to a second OTN switch for processing the SAN traffic iftraffic grooming is desirable, the processed SAN traffic is forwarded toits destination via the DWDM network as soon as the processed SANtraffic is received by the DWDM NE from the second OTN switch. Note thatthe process is also capable of receiving a second IP traffic from asecond IP router.

An advantage of employing a network configuration using DWDM NE orswitch to communicate with DWDM network and EU's devices (i.e., IProuters, SAN servers, etc.) is that the network configuration is moreadaptable to on-demand network connection as well as future expansion.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art that,based upon the teachings herein, changes and modifications may be madewithout departing from this exemplary embodiment(s) of the presentinvention and its broader aspects. Therefore, the appended claims areintended to encompass within their scope all such changes andmodifications as are within the true spirit and scope of this exemplaryembodiment(s) of the present invention.

What is claimed is:
 1. A network switch coupled to a dense wavelengthdivision multiplexing (“DWDM”) network, comprising: a network interfacecoupled to a DWDM network and configured to provide interface with theDWDM network; a device interface coupled to the network interface andconfigured to interface with a network router facilitating communicationbetween the DWDM network and user devices; an optical transport network(“OTN”) bypass module coupled to the network interface and configured toselectively bypass at least a portion of traffic from a coupled OTNswitch in response to a predefined set of bypassing condition; and abypass multiplexer coupled to the OTN bypass module and configured tofacilitate selectively bypassing the traffic from the OTN switch inresponse to content of the traffic.
 2. The network switch of claim 1,further comprising a plurality of storage area network (“SAN”) input andoutput (“I/O”) ports coupled to the device interface and configured tofacilitate communication between a SAN server and the DWDM network. 3.The network switch of claim 2, wherein the SAN server having a DWDMtransceiver and is able to backup data at a remote location utilizingSAN.
 4. The network switch of claim 1, wherein the DWDM network is ableto transport information via a plurality of optical fibers and isconfigured to logically link multiple geographic distanced nodestogether for network communication.
 5. The network switch of claim 1,wherein the OTN switch having an OTN port is configured to process atleast a portion of the optical signals sent to the DWDM network.
 6. Thenetwork switch of claim 1, wherein the network router is a firstInternet Protocol (“IP”) router coupled to an IP port of the networkswitch and configured to facilitate IP traffic between a user and theDWDM network.
 7. The network switch of claim 1, further comprising areconfigurable optical add-drop multiplexer (“ROADM”).
 8. The networkswitch of claim 7, wherein the ROADM is configured to route opticalsignals between an SAN server, IP router, and the DWDM network.
 9. Thenetwork of claim 1, wherein the OTN switch includes a grooming moduleconfigured to provide traffic grooming involving traffic flows from anSAN and the IP router.
 10. The network of claim 1, further comprising anetwork processing module able to receive SAN traffic from an SAN serverand forward at least a portion of the SAN traffic to the OTN switch fortraffic grooming.
 11. An optical network configuration, comprising: afirst storage area network (“SAN”) server configured to process SANtraffic and a first Internet Protocol (“IP”) router configured to handleIP traffic; a first optical transport network (“OTN”) switch configuredto process at least a portion of optical signals before sendingprocessed signals to their destination via a wavelength divisionalmultiplexing (“WDM”) network; a first WDM switch, coupled to the firstSAN server, the first IP router, and the first ONT switch, configured toselect one of the first SAN server, first IP router, and first OTNswitch to communicate with the WDM network in accordance with a set ofpredefined conditions; a second SAN server configured to process SANtraffic and a second IP router configured to handle IP traffic; a secondOTN switch configured to process at least a portion of optical signalsbefore sending processed signals to their destination via the WDMnetwork; and a second WDM switch, coupled to the second SAN server, thesecond IP router, and the second ONT switch, configured to select one ofthe second SAN server, second IP router, and second OTN switch tocommunicate with the WDM network in accordance with a second set ofpredefined conditions.
 12. The configuration of claim 11, wherein theWDM network is a dense wavelength division multiplexing (“DWDM”) networkconfigured to transport optical information; and wherein the first WDMswitch includes a SAN port, an IP port, an input OTN port, an output OTNport, and a DWDM output port.
 13. The configuration of claim 12, whereinthe SAN port is coupled to the first SAN server and the IP port iscoupled to the first IP router; and wherein the input OTN port and theoutput port are coupled to the first OTN switch.
 14. The configurationof claim 11, wherein the first DWDM switch includes a reconfigurableoptical add-drop multiplexer (“ROADM”) for routing at least one of theSAN traffic and the IP traffic.
 15. The configuration of claim 11,wherein the first OTN switch includes a grooming module configured toprovide traffic grooming involving in traffic flows from the first SANand the IP router.
 16. The configuration of claim 11, wherein the firstDWDM switch includes a network processing module able to receive SANtraffic from the first SAN and forward the SAN traffic to the OTN switchfor traffic grooming.
 17. A method for transmitting data over acommunication network, comprising: receiving first Internet Protocol(“IP”) traffic from a first IP router via a dense wavelength divisionalmultiplexing (“DWDM”) optical signal; identifying which portion of thefirst IP traffic to bypass a first OTN switch; directing at least aportion of the first IP traffic to the first OTN switch from an OTNoutput port of a DWDM switch for processing the first IP traffic;transmitting processed first IP traffic via an output port of the DWDMswitch to a DWDM network after receiving the processed first IP trafficfrom the first OTN switch; receiving a storage backup transmission froma first storage area network (“SAN”) server via a stream of WDM opticalsignals; and redirecting the storage backup transmission to the firstOTN switch from the OTN output port of the DWDM switch for processingthe storage backup transmission.
 18. The method of claim 17, wherein theredirecting at least a portion of the IP traffic includes assigning afirst ten (10) gigabits (“Gb”) of 14 Gb IP traffic to a first ten (10)Gb per second (“Gb/s”) optical link and sending the first ten (10) Gb toits destination through an output port of the DWDM switch via the DWDMnetwork.
 19. The method of claim 17, further comprising: receivingsecond IP traffic from a second IP router via a second DWDM opticalsignal; identifying which portion of the second IP traffic to bypass thesecond OTN switch; directing at least a portion of the second IP trafficto the second OTN switch from an OTN output port of a second DWDM switchfor processing the second IP traffic; and transmitting processed secondIP traffic via an output port of the DWDM switch to a DWDM network afterreceiving the processed second IP traffic from the first OTN switch.